Identification of new targets and novel treatment strategies for chronic myeloid leukemia. Ralph B. Arilnahaus. Ph.D.- My laboratory has published new information on several key proteins in chronic myelogenous leukemia that are regulated by the Bcr-Abl oncoprotein. These proteins are lipocalin 2 (NGAL/24p3), Jak2 and Bcr. We were first to discover the role of lipocalin 2 in Bcr-Ab1 induced leukemia. Our recent studies with 24p3 null mice showed that 24p3 secretion by Bcr-Abl+ cells is a requirement for leukemia induction by Bcr-Abl in a mouse model. Regarding Jak2, we show that it is part of a large signaling network. Inhibition of Jak2 induces apoptosis in imatinib-sensitive/resistant Bcr-Abl + cells, in CML cell lines and in cells from blast crisis CML patients. Concerning Bcr, wild-type Bcr protein inhibits the oncogenic function of Bcr-Abl but serine/threonine kinase-defective Bcr enhances the oncogenic effects of Bcr-Abl.
Aim #1, Develop a monoclonal antibody that blocks lipocalin 2 (NGAL/24p3) activities induced by Bcr-Abl, and investigate the effects in mouse leukemia models. Our goal is to interfere with NGAL function for treatment of CML in combination with other therapeutic regimens such as Gleevec therapy.
Aim #2, Investigate the mechanistic effects of new Jak2 inhibitors in imatinib-sensitive and resistant CML cell lines, patient cells, and in patient cells from advanced stages of CML with the long-term goal of doing clinical trials in imatinib-resistant CML and late stage CML (with Dr. Cortes). We hypothesize that a potent Jak2 inhibitor will be useful in the treatment of drug-resistant CML as well as in all stages of CML because of the dominant role of Jak2 in oncogenic signaling in CML cells. We have identified a new Jak2 inhibitor (WP1193) that disrupts the Bcr-Abl/Jak2/HSP90 signaling network complex leading to apoptosis of drug-resistant CML cells and blast crisis CML cells. Surprisingly, preliminary results indicate that the Jak2 kinase phosphorylates Tyr 177 of Bcr-Abl, which upon Jak2 inhibition drastically reduced Grb2 binding to the network complex and caused the disruption of the Ras and PI-3 kinase signaling pathways. Importantly, Jak2 inhibition also drastically reduced Bcr-Abl protein levels, causing down-regulafion of STAT5 and STAT3 signaling. Thus, Jak2 inhibition disrupts many If not all oncogenic effects in CML.
Aim #3, Invesfigate the role ofthe Bcr Ser/Thr kinase in regulating Bcr-Abl oncogenic activity. We will search for mutations in the Bcr kinase domain, as we hypothesize that such mutations play a role in CML disease progression.
The outcome of these studies will lead to new strategies to treat drug-resistant forms of chronic myeloid leukemia and advanced stages of CML. Each strategy was based on published research generated by the Ariinghaus lab over the last five years of support from this P01 grant and a ROI grant from NIH.
|Eiring, A M; Page, B D G; Kraft, I L et al. (2015) Combined STAT3 and BCR-ABL1 inhibition induces synthetic lethality in therapy-resistant chronic myeloid leukemia. Leukemia 29:586-97|
|Zhang, Weiguo; Gao, Chen; Konopleva, Marina et al. (2014) Reversal of acquired drug resistance in FLT3-mutated acute myeloid leukemia cells via distinct drug combination strategies. Clin Cancer Res 20:2363-74|
|Tao, Wenjing; Leng, Xiaohong; Chakraborty, Sandip N et al. (2014) c-Abl activates janus kinase 2 in normal hematopoietic cells. J Biol Chem 289:21463-72|
|Thall, Peter F; Nguyen, Hoang Q; Zohar, Sarah et al. (2014) Optimizing Sedative Dose in Preterm Infants Undergoing Treatment for Respiratory Distress Syndrome. J Am Stat Assoc 109:931-943|
|Mak, P Y; Mak, D H; Mu, H et al. (2014) Apoptosis repressor with caspase recruitment domain is regulated by MAPK/PI3K and confers drug resistance and survival advantage to AML. Apoptosis 19:698-707|
|Jin, Ick Hoon; Liu, Suyu; Thall, Peter F et al. (2014) Using Data Augmentation to Facilitate Conduct of Phase I-II Clinical Trials with Delayed Outcomes. J Am Stat Assoc 109:525-536|
|Benjamini, Ohad; Kantarjian, Hagop; Rios, Mary Beth et al. (2014) Patient-driven discontinuation of tyrosine kinase inhibitors: single institution experience. Leuk Lymphoma 55:2879-86|
|Havelange, Violaine; Ranganathan, Parvathi; Geyer, Susan et al. (2014) Implications of the miR-10 family in chemotherapy response of NPM1-mutated AML. Blood 123:2412-5|
|Ohanian, Maro; Kantarjian, Hagop M; Quintas-Cardama, Alfonso et al. (2014) Tyrosine kinase inhibitors as initial therapy for patients with chronic myeloid leukemia in accelerated phase. Clin Lymphoma Myeloma Leuk 14:155-162.e1|
|Zabriskie, Matthew S; Eide, Christopher A; Tantravahi, Srinivas K et al. (2014) BCR-ABL1 compound mutations combining key kinase domain positions confer clinical resistance to ponatinib in Ph chromosome-positive leukemia. Cancer Cell 26:428-42|
Showing the most recent 10 out of 220 publications